Stranded 2.5mm T&E cable

[pc1966]

Recently a couple of threads have discussed T&E cable and it became apparent to me that the 2.5mm, which I have only ever seen as solid core, is available with the live cores in 7-strand (rather like the old 7/.029" imperial size, though with solid CPC and not the 3-strand seen before). In fact CEF list it as available (but not stocked locally, as usual, and no maker information):

H6242Y 2.5mm² PVC T+E Twin and Earth Stranded Core Cable Grey (100m Drum)

Twin & earth with stranded cores

www.cef.co.uk

Does anyone know of specific use-cases where this is specified?

Has it simply been familiarity with previous installations using the stranded imperial size?

 

[SJD]

I find virtually nothing I want is in stock locally from CEF, but you can order it on free delivery (over £50), they apear to have some 15km of it in stock!

 

[Deleted account]

Stranded vs. Solid Wire Cable: How to Choose

Both shielded and unshielded twisted-pair copper cable comes in either stranded or solid wire versions. There are plenty of considerations when it comes to choosing one or the other, including standards, environment, application, and cost. Let’s take a look at the differences and considerations...

www.flukenetworks.com

have a read. Interesting. every day is a learning day.

 

[pc1966]

I find virtually nothing I want is in stock locally from CEF, but you can order it on free delivery (over £50), they apear to have some 15km of it in stock!

Indeed, I have found their web site is very good and delivery also prompt. But prices are "variable" and hardly handy for small items or if you discover you need it same day!

 

[pc1966]

Stranded vs. Solid Wire Cable: How to Choose

Both shielded and unshielded twisted-pair copper cable comes in either stranded or solid wire versions. There are plenty of considerations when it comes to choosing one or the other, including standards, environment, application, and cost. Let’s take a look at the differences and considerations...

www.flukenetworks.com

have a read. Interesting. every day is a learning day.

Until they say:
And because the cross section of a stranded conductor is not all copper (there’s some air in there), they also have a higher DC resistance than solid cables.
WTF? Not the same CSA then!

 

[timhoward]

I find virtually nothing I want is in stock locally from CEF, but you can order it on free delivery (over £50), they apear to have some 15km of it in stock!

If they say "in stock" it helpfully means they might be able to get it tomorrow.
And the classic was when I ordered 45m of 3 core SWA online, and it turned up as 20m piece and a 25m piece.

 

[telectrix]

If they say "in stock" it helpfully means they might be able to get it tomorrow.
And the classic was when I ordered 45m of 3 core SWA online, and it turned up as 20m piece and a 25m piece.

with a resin joint thrown in?

 

[Deleted account]

Until they say:
And because the cross section of a stranded conductor is not all copper (there’s some air in there), they also have a higher DC resistance than solid cables.
WTF? Not the same CSA then!

Yes surely they are not including the air as part of the cross sectional area of the cable. Maybe they do?

 

[SJD]

Until they say:
And because the cross section of a stranded conductor is not all copper (there’s some air in there), they also have a higher DC resistance than solid cables.
WTF? Not the same CSA then!

The 2.5mm2 stranded is 7x 0.67mm dia conductors, which works out at 2.47mm2 CSA. Probably the 0.67mm dia is rounded, so that the cable is actually 2.50mm2 CSA. But the air would make the overall cable very slightly larger physically.

 

[timhoward]

with a resin joint thrown in?

Nope! When I phoned they said they were showing 140m in stock but it was all in lengths of 25m or less.
Peter Cook and Dudley Moore - "Lengths" came to mind....
(for younger members - this is the sketch in question

)

On this one a joint would have had to be above ground surface clipped and even I have some standards.....

 

[UNG]

Recently a couple of threads have discussed T&E cable and it became apparent to me that the 2.5mm, which I have only ever seen as solid core, is available with the live cores in 7-strand (rather like the old 7/.029" imperial size, though with solid CPC and not the 3-strand seen before). In fact CEF list it as available (but not stocked locally, as usual, and no maker information):

From another thread

Just found this Datasheet

On page 3 it shows *H6242YST 2 x 2.5 Nominal stranding of conductor 7 / 0.67 & CPC 1 / 1.38 (1.5mm²)

So stranded 2.5 is still manufactured and the sheet also shows stranded 1.5

The datasheet is from Doncaster Cables website and they appear to be the only company listing it

Does anyone know of specific use-cases where this is specified?

Has it simply been familiarity with previous installations using the stranded imperial size?

Pilkingtons Glass always specified it for their offices although I've not done any electrical work on their offices for 25 -30 years found it more lucrative doing the CCTV, covert CCTV and alarm systems on their sites. Back in the early 80's when I came out of my time a new glass plant was being built in St Helens and once a week (Friday afternoon overtime ) for a number of weeks I had to go to AEI in Leigh and collect 4000m of 2.5 stranded T&E

I think some of specifications going back awhile called for only stranded cables to be used i.e. 6491x conduit cable and this was carried over into T&E where it was used

 

[nicebutdim]

Until they say:
And because the cross section of a stranded conductor is not all copper (there’s some air in there), they also have a higher DC resistance than solid cables.
WTF? Not the same CSA then!

I read that part as being relevant to termination, rather than CSA - unless you tighten down and mash the strands, there may not be the same area in contact with terminal.

 

[MJPD29]

I find cef is absolutley useless unless you solely do domestic work, and even then it's probably crap

 

[Rockingit]

I find cef is absolutley useless unless you solely do domestic work, and even then it's probably crap

CEF has always been impersonal, over priced and inefficient. Must be at least a year since I’ve used them, especially with Rexel also doing web based order/deliver.

 

[UNG]

I've never trusted CEF and have very rarely used them after a manager at the local branch nearly exited the building through the plate glass window frontage of the branch with my help when he decided to slag me, my business partner and our company off when the trade counter had a number of customers in and that was 30ish years ago
I remember one of the big companies locally doing an audit and finding that CEF had overcharged them or sent invoices for goods not supplied to the tune of around £100k